Conventional refrigeration devices are widely known that are provided with a refrigerant circuit in which a compressor, a radiator, a supercooler, a first expansion valve, a liquid receiver, a second expansion valve, and an evaporator are connected in sequence (see Japanese Laid-open Patent Application No. 10-115470, page 5, right column, line 40 through page 6, left column, line 45 and FIG. 8, for example).